Edge trimmer for advancing sheet material



May 29, 1956 s. s. MINER 2,747,665

EDGE TRIMMER FOR ADVANCING SHEET MATERIAL Filed Feb. 5, 1954 ATTORNEYUnited States Patent EDGE- FGR SHEET MATERIAL Samuel; 5.. Miner,lVIishawaha, Ind, assignor to United States Rubber Company, New Yorlk N.Y.,.a corporation. ofNew Jersey Application. February 3,1954j.Serial'1Noa40fl ,865 1'0Claims. c1. 164-39).

This invention relates to a trimmer for. sheet material, and. morespecifically it relates to a trimmer adapted to trim automaticallyexcess coating from a continuously advancing web of coatedfabric or thelike.

In. producing coated fabrics and similiar articles, frequently thefabric or other base. has applied. thereto an excess. of coating.material which extends beyond the edges ofthe base. For example coatedfabrics. are commonly produced by a calender coating process in which acontinuous thin coating sheet of rubber, resinor. the like several. feetWide and of continuous lengthv is pro.- duced' on a. calender. This.coating sheet advances continuously through the nip of a final pairof'the calender roll's simultaneously with a base sheet of fabric, paperor the; like several feet in width and of great length. As the twosheets pass through this nip, the coating. sheet is pressed onto thebase sheet to form a coated. fabric or the like. As this product leavesthe nip of these rolls, the coating. generally extends beyond the sidesof the base some; distance, and before the laminate is ready for sale oruse this excess should be. trimmed therefrom so the base and coating arecoextensive in the finished product:

It is an object ofthis' invention to provide a trimmer adapted to trimexcess coating material from a base sheet to produce thedesired finishedproduct.

in accordance with this invention there is provided a roller" that ismounted to roll along. the back" of the laminate which is to be trimmed.The laminate is led pastthisroller in such a manner thatthe' roller maycon.- tact and roll along the edge ofthe'base sheet: The roller ismounted such that it' also may" be translated along. a fixed path whichextends transversely of the base sheet to inteieept: the line formed bythe edge of the base sheetin a substantial" angle. Consequently theroller may be' positioned such that it will roll either on the hasesheet or on' the overhanging edge of the coating sheer. Iii accordancewith this" invention means are providiscl tocause the roller to assume aposition in it's' fiixed path where it Will roll precisely on the edgeof thebasesheet'as'thebase sheet moves therepast. A knifeis. mounted infi'xed relation to the roller, and is positioned to. pierce thelaminate; Since means are provided to maintain the-roller rolling alongthe edge oh the base sheet; thi'sknifemaybemounted to cut" the excesscoating material from the laminate precisely along the edge of thishase' as the laminate progresses therepast or the knife may be spaced apredetermined distance fromthisedge to trim' only a: parfi of thecoating should such a finishediproducti be" desired.

In: accordance with this invention the means to maintain the rollerrolling precisely alongthe edge of" the base fabridcomprises an axle forthe roller which is mounted at a slight angle; to the line formed bythe-edge oh" the base fabric. The roller' rotates about this; axis and.consequently theroller tends to=roll at a slight angle to the edge ofthe base. Consequently" as the: laminate passes' the roller itexerts aforce: thereon which tends'to' translate the roller in an. angulardirection with. respect to. theedge of the base. Since the roller ismounted such thatit may lie-translated along a fixed path. disposed inan angular relation to the edge of the base, the roller: may betranslated in response to this. force. Means are provided. to. exert a.uniform. force on the roller. tending to resist this translation. Thisforce: is selected such that. itis great enough: to overcome thetendency of the roller to be. translated when it is in frictionalengagemenL with one of the. elements in the laminate, i. e. thecoatingor the. base, but it is. not great enough to overcome. thistendency to move: when the roller is in frictional'. engagement with theother element in the laminate. Consequently when. the roller is runningon the first elementof. the. laminate the. force will move the rollertoward the. edge of. the base until itruns: on. theother element. ofthe. laminate- Conversely when the roller runslonthe second. element of.the laminate, the force: on the. rollerwill overcome this fixedforceand: move the roller toward the firstv element of the laminate.Consequently a position of equilibrium willbe; achieved where the rolleris. running. partially on the base and. partially on. the coating, i. e;along the: edge of. the base, and the roller: will follow this.edgeshould itdeviate from a straight: line as the. laminate: is ledpasttherolleru In. one specific-embodiment of-. this invention the rollercomprises. a. wheel thatis mounted. on. an: axle. This axle.-is; mountedona. carriage. in amannen such that the Wheel is: canted inwardlyslightly withrespect to theedge oflthebase; Thefixedforceais providedby. a second-wheel mounted on an. axleon the. same carriage. This secondwheel=is canted: outwardly toward. the edge of. the. base; consequentlythe two wheels. are canted inwardly toward each otherandtthe'second-wheel runs always on the-base. The carriage is mountedfor movement along a shaft disposed in-anangular direction to the edgeof'thet base. A. knife is. mounted on. the carriage. in fixed relationin spacewto the first wheels As the laminate isled past this. carriageincontact with both wheels, the second wheel which is always. in contactwith the base will, because. of. itsv canted position. in relation to:the direction of movement of: the laminate therepast, tend to move thecarriage along the shaft in onedirection; inc. the second-will tend torun; 01f the. base. Conversely the first wheel which is adaptedto run.along: the. edge of the base will tend to move the carriagein the otherdirection alongtheshaft; i.- e.. the-first wheel will tend to run ontothe base. The. surfaces. of the wheels are made suchthat when.bothwheels. are runningonthe base, the second wheel has a greaterrict-ional. drag thereon than the. first and consequently the carriagewill move inresponse. to. the. urging. of this second wheel. However thesurfaces of the wheels: are such that when. the fir-st wheel is runningonthe coating, it. exerts a force on the carriage sufficientto overcomethanofthesecond wheel running"; on the base This-may be. achieved easilybecause the natures of the. coating and basev are such that the.coating. will exert a. greater drag.v on the wheel. than will the base.Consequently as the fabric. is led past: thev carriage, the. carriagewill assumea position onits shaft such that. the. first wheel is runningpartially on the overhanging edge of the coating. and. partially on the.base and this wheel will. followthis edge. oi the base as the laminateis. led therepast.. A knife is mounted on the carriage in a position to.trim=the lan1ii1ate,,and sincev the carriage follows the edge of. thebase this knife will trim the excess coating from the laminate.

For a Better; understanding of the nature of this. in= vention,reference should be hiad to the following detailed description when readin" conjunction with the accompanying drawing, wherein:

Fig. l is an end elevational view of the trimmer in accordiance withthis invention showing it mounted in the exit end of the nip of a pairof calender rolls and illustrating the use of the trimmer to trim excesscoating stock from the edge of a coated fabric; and

Fig. 2 is a plan view of the trimmer in accordance with this inventionlooking substantially along line 2-2 of Fig. 1.

Referring now to the drawing, there is illustrated an embodiment of thetrimmer in accordance with this invention which is well suited fortrimming excess coating stock from a sheet of coated fabric. In thedrawing, this trimmer is illustrated as running in the exit end of a nipof calender rolls 10, 11. These rolls may constitute the final pair ofrolls of a calender used to produce a coated fabric. As is well known inthe rubber industry, the calender (not shown) calenders a continuoussheet of coating such as rubber, resin or the like to the desired gauge,and a base sheet such as fabric, paper or the like is then ledsimultaneously with this coating through a final pair of calender rollswhere the coating is pressed onto the base sheet to produce the coatedfabric. Since the calender and the method of calender coating fabricsare well known and form no part of this invention, they will not befurther described here.

As best shown in Fig. 2, the laminate CF as it leaves the calender hasthe coating C applied to the base sheet F. Generally there is a narrowexcess of coating 12 which overhangs the edge 13 of the base sheet F. Itis desirable that this excess coating 12 be trimmed from the base sheetalong the edge 13 of the base sheet, so that the coating and base sheetare coextensive in the finished laminate. The trimmer in accordance withthis invention is well adapted to trim this excess 12 from the coatedsheet continuously and automatically.

In the embodiment shown in the drawing, the trimmer comprises a firstwheel 14 which is rotatably mounted by means of bearings 15 on an axle16. This axle 16 is mounted at a slight angle to the edge 13 so that thewheel 14 is canted inwardly slightly toward the base sheet from thisedge. This wheel 14 is urged against the laminate CF and against theroller 10 of the calender by means to be described, so that as thelaminate CF advances in the direction indicated by the arrow it willtend to rotate the wheel or roller 14. As seen in Fig. 2, the movementof the laminate CF past the roller 14 will exert a orce on this rollerwhich tends to make it roll off the excess coating 12 and onto the sheetF, i. e. downwardly as seen in Fig. 2. This axle 16 is mounted on acarriage that is constrained to move only along a path which lies in anangular direction with respect to the edge 13 of the base sheet.

In the embodiment shown in the drawing, this carriage comprises a post17 that is fixed in a mounting 18 therefore. The post 17 carries on itsopposite end a second wheel 19 that is adapted to run on the base sheetF. As shown in Fig. 2, this wheel 19 is rotatably mounted by means ofbearings 20 on an axle that is canted toward the edge 13 of the basesheet F so that the wheels 14, 19 are canted inwardly toward each other.Consequently as the wheel 19 rolls along the base F it will tend to rolloff the base onto the excess coating 12, i. e. upwardly as seen in Fig.2. Therefore it will be seen that rollers 14 and 19 each exert a forceon the post 17, which forces since they act in opposite directions tendto counterbalance each other.

The mounting 18 for the post 17 is fixed to a sleeve 22 by connectingmember 21. This sleeve 22 embraces a shaft 23 that extends in an angulardirection with respect to the edge 13 of the base sheet. In theembodiment shown, the shaft 23 extends substantially at right angles tothe edge 13 entirely across the calender. The sleeve 22 is mounted onthe shaft 23 for sliding movement longitudinally of this shaft by meansof three spaced rollers 24 at each end that are mounted on axles 25 4carried by straps 26 which are fixed to the sleeve 22. Consequently thesleeve 22 may move freely along the shaft 23 in response to the urgingsof the rollers 14, 19 to move these wheels and a cutting knife, to bedescribed, laterally of the laminate CF. Because the sleeve 22 floats onshaft 23, the sleeve may also be rotated about this shaft, andconsequently the rollers 14, 19 may be moved into or out of engagementwith the laminate CF. I

A lever 27 fixed to the sleeve 22 on the opposite side thereof from post17 carries a counterweight 28 thereon. This counterweight tends torotate the sleeve 22 about the shaft 23, and consequently urges therollers 14, 19 upwardly into firm engagement with the laminate CF andthe upper calender roll 10. This sleeve 22 also carries a knife mounting29 to which a knife 30 is fixed by means of bolt 31. The blade of knife30 is positioned to pierce the laminate CF substantially in line withwheel 14 in the embodiment shown.

In the operation of the trimmer, the wheels 14 and 19 are urged againstthe laminate CF by the counterweight 28. As this laminate runs pastthese wheels, they will rotate about their axes, and because of theircanted position, they will also tend to slide along the laminate.Consequently the wheel 14 will urge the carriage downwardly as seen inFig. 2 and wheel 19 will urge the carriage upwardly as seen in the samefigure. Since the wheel 19 is positioned to run always on the base sheetF it will exert a uniform force on the carriage tending to move it alongthe shaft 23. As the wheel 19 moves the carriage towards the edge 13 ofthe fabric, the wheel 14 will be moved outwardly toward the overhangingcoating 12. The device is constructed in a manner such that the forceexerted by the wheel 14 on the carriage when l the wheel 14 is runningon the base F is less than the force exerted by the Wheel 19 on thecarriage when wheel 19 is also running on the base F. Consequently thecarriage will move to the edge 13 of the base F until the wheel 14 isrunning on the overhanging coating 12. At that point since the coating Coffers a much greater frictional resistance to the sliding of the wheel14 there along than does the base F of fabric, paper or the like, theforce exerted on the carriage by the wheel 14 will increase materially.Wheel 14 is constructed such that the force exerted by it when it is onthe coating is greater than the force exerted on the carriage by thewheel 19 running on the base F. Consequently the wheel 14 will then tendto move the carriage to a position where the wheel 14 is running on thebase F.

A position of equilibrium will be achieved when the wheel 14 is runningprecisely along the edge 13 of the base F, so that the wheel 14 isrunning partially on the base F and partially on the overhanging portion12 of the coating C. Consequently if the edge 13 on which the wheel 14is running remains straight, the carriage will assume a fixed positionon shaft 23. However, should the edge 13 depart from a straight line,the wheel 14 would be running on either the base or the overhangingcoating 12 depending upon the direction of departure, and the unbalancethus set up would shift the carriage along shaft 23 until the wheel 14were once again running along the edge 13 of the base. Thus it will beseen that the wheel 14, and consequently the carriage, will followprecisely the edge of the base as it is led therepast. The knife 30being mounted on this carriage will similarly follow the edge 13 of thebase to trim the overhanging portion 12 of the coating C from thelaminate CF. This edge 12 as best shown in Fig. 1 may be led with theroll 10 upwardly into the bank of coating stock to be reused therein ifdesired.

The forces exerted on the carriage by the wheels 14 and 19 may bebalanced by any suitable construction of the apparatus. In theembodiment illustrated this is done conveniently by knurling the surfaceof wheel 19, and by cutting a plurality of circumferential grooves 38 inwheel 14. When the grooved and knurled wheel are- 2374?, can

both: running on base E, the knurled wheelrwill exert: a greater thruston the: carriagev than the grooved wheel, but whe'n grooved wheel'1'4'isrnnnington the: excessrcoat ing 12, the grooved wheel will exertl agreaten'thrust on the carriage than the knurled wheeli running'oni thebase FL Alternatively,.the surfaces of wheels- 1 4 and 19" may be made'more orless similar, and the angles of cant of thesewheels may beadjusted in amanner about to be described untilthe desired balance isreached.

The trimmerin accordance=with this invention may-be made adjustable toadapt it to trim excess coating-having differentproperties from basesheets or'to provide the desired thrust balance between the wheelst Thusin the embodiment shown in the drawing; the axle 16 of wheel 14 isadjustably mounted on post 17 so that the degree of canting of' thewheel 14 with respect to the edge 13 may be varied as desired. This axle16 ismounted on a carrier 32 which is mounted on a pivot 3 3 at the endof post-'1-71 The carrier 32' is fitted'in a slot in=post 17 and on its"inner end has aninclined-- shoulder 34 that is projectible abovethesurface of the post- 1-7i The post 17 base threaded portion adjacentthis-inclined shoulder $4 and a nut 35 is threaded thereupon formovement longi tu'dinallyof the post 17-. As the-nut 35 is moved towardwheel 14= along the threads on post 1 7-, a bearing surface on nut 35bears against shoulder 34 to-depress this shoulder' within the slot inpost 17 and thus'pivot carrier 32 about its pivot 33' to therebyincrease: the anglebetween shaft 16 and edge 13: A spring 3'6held by setscrew 37 extends through an opening in post 17 to bear' against theundcredge of carrier 32 to urge should'er 34 against thenut 35;Consequently if the nut 35 is backed oif shoulder 34; spring3'6 willurge carrier32 topivot'a'bout its pivot 33' and therebydecreasetheangle: of shaft 16 with respect to the edge 13 of the'base F.In' thi'smanner' the inclination of wheel 14 with respect to thedirection of'travel' of the laminate CF therepastmay'be varied to varythe lateral thrust exerted by this wheel on the carriage; Bythus varyingthe inclination of wheel 14, the apparatus may be adapted to work withgum stocks or bases having different frictional characteristics withrespect to the surface of the wheel 14. So also i'f.desired the angle ofinclination of wheel 19 with respect to edge 13' may be variedby'similarly' mounting wheel 19.

So also the, position of knife with" respect to wheel 14 may be varied.In the embodiment shown in the drawing this is accomplished by providinga hollow mounting 18 through which the post 17 slidably extends. Thepost 17 may be adjusted to any desired position within mounting 18, andthe post 17 may be tightened in such position by means of a set screw 39which extends through the mounting 18 and is adapted to bear against thepost 17 therein. Also the apparatus is adaptable to trimming the edge 12from either side of the coated laminate CF. This may be provided byfixing the mounting 18 pivotally in the member 21, so that mounting 18,post 17 and wheels 14 and 19 may be rotated about an axis through member21 and extending at right angles to the axis of post 17,

Having thus described my invention, what I claim and desire to protectby Letters Patent is:

1. A trimmer adapted to trim sheet material when advancing in a givendirection and having a juncture of two materials having differentco-elficients of friction with a given object, said juncture having acomponent of its length extending in the direction of advance of saidsheet material, said trimmer comprising a carriage, means adapted tosupport said carriage for movement along a path disposed in angularrelation to the juncture and having a component of its length transverseto the direction of advance of the sheet material, a roller on saidcarriage adapted to be positioned to roll along the juncture infrictional engagement with the sheet material, said roller being cantedon said carriage with respect to the direction that the sheet materialis adapted to advance co-efiicient offriction with said roller, saidmeans;beingadapted.=to.=develop.- a force whichis sufiicient to countefiact the; transverse force of said roller on said carriage when. said'lroller is rolling along th'e-juncture-ofthe two materials, and cutting:means,v carried by said carriage adapted to cut: the: sheet material;-whereby: said carriage is adapted: to be. moved' along the pathto aposition wherein: said; cutting: means. may be positioned in substantially constant relation with the juncture of the sheet material.

21 A trimmeradaptedi to trim a web-of. laminated sheet material whenadvancing ina given direction-and having a. juncturenformedlby'anoverhanging edgeiof'one material having a differentcoeefficient offiricti'on' with agiven object. than the other material in the laminateforming the: juncture, said juncture-having a major component of itslength. extending in the direction of advance ofi'said sheet materiaLsaid trimmer comprising a carriage; means adapted to supportsaidcarriage for movement along a path disposedin angular relation to' thejunctureand havinga component of itslength= transverse tothedirectionof: advance: of. the sheet material, a whecl on said carriage adapted tobe positioned to roll along the juncture in frictional engagementwiththe sheet material, sai h wheel being. canted.- on said carriage: with:respect to the dime tion: that the: sheet material is adapted to advancepast the: carriage and in a direction toroll toward the-material havingthe: lesser co-eflicient of friction with said wheel; means: to urge.said carriage in a directionadaptedto position said wheelon thatmaterial having'the" greater. co-efficient of. frictionwith: said.wheel, said means being adapted to: develop a force which is sufii'cientto-counter act the transverse. force of said wheel onsaid carriagewhensaid wheel is rolling along the juncture of the two materials, and aknife carried bysaid carriage adapted to cut: the sheet" material as itadvances, whereby said carriage is: adapted to be: moved along the pathto aposition wherein said knife may be positioned in substantiallyconstant relation with; the: juncture oi the: sheet material.

3. A trimmer adapted to trim a: web 0h laminated sheet' material whenadvancingv in a. given: direction and hav ing, ajunctureformed byanoverhangingedgeof one of the materials in the laminate that has adifferent co-efiicicnt of friction with a given object than the othermaterial in the laminate forming the juncture, said juncture having amajor component of its length extending in the direction of advance ofsaid sheet material, said trimmer comprising a carriage, means adaptedto support said carriage for movement along a path disposed in angularrelation to the juncture and having a component of its length transverseto the direction of advance of the sheet material, a first wheel on saidcarriage adapted to be positioned to roll along the juncture infrictional engagement with the sheet material, said wheel being cantedon said carriage with respect to the direction that the sheet materialis adapted to advance past the carriage and in a direction to rolltoward the material having the lesser coefficient of friction with saidwheel, a second wheel on said carriage adapted to be positioned to rollalways on the material having the lesser coefficient of friction withsaid first wheel and in frictional engagement therewith, said secondwheel being canted on said carriage with respect to the direction thatthe sheet material is adapted to advance past the carriage and in adirection to roll toward the material having the greater coeflicient offriction with said first wheel, and cutting means carried by saidcarriage adapted to cut the sheet material, whereby said carriage isadapted to be moved along the path to a position wherein said cuttingmeans may be positioned in substantially constant relation with thejuncture of the sheet material.

4. A trimmer adapted to trim a coated sheet when advancing in a givendirection and having a juncture formed by an overhanging excess ofcoating having a diflerent coefiicient of friction with a given objectthan the base sheet, said juncture having a major component of itslength extending in the direction of advance of said coated sheet, saidtrimmer comprising a carriage, means adapted to support said carriagefor movement along a path disposed in angular relation to the junctureand having a component of its length transverse to the direction ofadvance of the sheet material, a first wheel on said carriage adapted tobe positioned to roll along the juncture in frictional engagement withthe coated sheet, said wheel being canted on said carriage with respectto the direction that the coated sheet is adapted to advance past thecarriage and in a direction to roll away from the overhanging excess ofcoating and toward the sheet, a second wheel on said carriage adapted tobe positioned to roll always on the sheet and in frictional engagementthere with, said second wheel being canted on said carriage with respectto the direction that the coated sheet is adapted to advance past thecarriage and in a direction to roll off of the sheet and onto theoverhanging excess of coating, and a knife carried by said carriageadapted to cut the excess of coating, whereby said carriage is adaptedto move along the path to a position wherein said knife may bepositioned in substantially constant relation with the juncture formedby the overhanging excess of coating.

5. A trimmer adapted to trim a web of coated sheet material whenadvancing in a given direction and having a juncture formed by anoverhanging excess of coating having a greater coefficient of frictionwith a given object than the base sheet, said juncture having a majorcomponent of its length extending in the direction of advance of saidcoated sheet material, said trimmer comprising a carriage, means adaptedto support said carriage for movement along a path disposed in angularrelation to the juncture and having a component of its length transverseto the direction of advance of the sheet material, an axle carried bysaid carriage, said axle being canted inwardly with respect to thedirection that the coated sheet is adapted to advance past the carriage,a first wheel rotatable on said axle and adapted to be positioned toroll along the juncture in frictional engagement with the coated sheetmaterial, a second wheel carried by said carriage adapted to bepositioned to roll always on the base sheet and in frictional engagementtherewith, said second wheel being canted on said carriage with respectto the direction that the sheet material is adapted to advance past thecarriage and in a direction to roll toward the overhanging excess ofcoating, and a knife on said carriage adapted to cut the overhangingexcess, whereby said carriage is adapted to be moved along the path to aposition wherein said knife may be positioned in substantially constantrelation with the juncture formed by the overhanging excess of coating.

6. A trimmer in accordance with claim 5 wherein said axle is movable tovary the angular relation between said first wheel and the linepresented by the advancing edge of said sheet.

7. A trimmer in accordance with claim 5 wherein said first wheel has alesser coeflicient of friction with said sheet than said second wheel.

8. A trimmer for an advancing web of coated sheet material having anoverhanging excess of coating having a greater coeflicient of frictionwith a given object than the base sheet, the juncture between saidexcess of coating and said sheet material having a component of itslength extending in the direction of advance of said coated sheetmaterial, comprising a shaft extending transversely of the advancingweb, a carriage on said shaft mounted for movement there along, a firstwheel on said carriage positionable to roll along the edge of saidsheet, said wheel being canted with respect to the edge of said sheet ina direction to roll toward the sheet, a second wheel on said carriageadaptable to roll. always on said sheet, said second wheel being cantedinwardly toward said first wheel, said second wheel having a surface ofgreater coefiicient of friction with said sheet than said first wheel,said wheels being adapted to position said carriage along said shaft insubstantially constant relation to said edge and a knife carried by saidcarriage positioned to cut said Web along the line which said firstwheel traverses.

9. A trimmer in accordance with claim 8 wherein said carriage is mountedfor rotatable movement about said shaft, and including a counterweighton said carriage urging said wheels in contact with said web.

10. A trimmer in accordance with claim 8 wherein said first wheel ismounted on an axle and including movable means supporting said axle tovary the degree of cant between said first wheel and the edge of saidsheet.

No references cited.

1. A TRIMMER ADAPTED TO TRIM SHEET MATERIAL WHEN ADVANCING IN A GIVENDIRECTION AND HAVING A JUNCTURE OF TWO MATERIALS HAVING DIFFERENTCO-EFFICIENTS OF FRICTION WITH A GIVEN OBJECT, SAID JUNCTURE HAVING ACOMPONENT OF ITS LENGTH EXTENDING IN THE DIRECTION OF ADVANCE OF SAIDSHEET MATERIAL, SAID TRIMMER COMPRISING A CARRIAGE MEANS ADAPTED TOSUPPORT SAID CARRIAGE FOR MOVEMENT ALONG A PATH DISPOSED IN ANGULARRELATION TO THE JUNCTION AND HAVING A COMPONENT OF ITS LENGTH TRANSVERSETO THE DIRECTION OF ADVANCE OF THE SHEET MATERIAL, A ROLLER ON SAIDCARRIAGE ADAPTED TO BE POSITIONED TO ROLL ALONG THE JUNCTURE INFRICTIONAL ENGAGEMENT WITH THE SHEET MATERIAL, SAID ROLLER BEING CANTEDON SAID CARRIAGE WITH RESPECT TO THE DIRECTION THAT THE SHEET MATERIALIS ADAPTED TO ADVANCE PAST THE CARRIAGE AND IN A DIRECTION TO ROLLTOWARD THE MATERIAL HAVING THE LESSER CO-EFFICIENT OF FRICTION WITH SAIDROLLER, MEANS TO URGE SAID CARRIAGE IN A DIRECTION ADAPTED TO POSITIONSAID ROLLER ON THAT MATERIAL HAVING THE GREATER CO-EFFICIENT OF FRICTIONWITH SAID ROLLER, SAID MEANS BEING ADAPTED TO DEVELOP A FORCE WHICH ISSUFFICIENT TO COUNTERACT THE TRANSVERSE FORCE OF SAID ROLLER ON SAIDCARRIAGE WHEN SAID ROLLER IS ROLLING ALONG THE JUNCTURE OF THE TWOMATERIALS, AND CUTTING MEANS CARRIED BY SAID CARRIAGEK ADAPTED TO CUTTHE SHEET MATERIAL, WHEREBY SAID CARRIAGE IS ADAPTED TO BE MOVED ALONGTHE PATH TO A POSITION WHEREIN SAID CUTTING MEANS MAY BE POSITIONED INSUBSTANTIALLY CONSTANT RELATION WITH THE JUNCTURE OF THE SHEET MATERIAL.